TDK-Lambda ZERO-UP 200W User Manual

Contents

TDK-Lambda ZERO-UP 200W User Manual Manual pdf 35 page image

4.4.8 Output ON/OFF Control4.4.7 Foldback ProtectionThe ON/OFF circuit has two controls; a front panel pushbutton and a rear panel connection. priority isgiven to the rear panel connection.1. Foldback protection will shut down the power supply output if the load current exceeds the currentlimit setting level. This protection is useful when the load circuitry is sensitive to over currentcondition.2. To arm the Foldback protection, the FOLD pushbutton should be pressed so the FOLD LEDilluminates. At this condition transition from Constant Voltage to Constant Current mode will activatethe Foldback protection.3. Activation of the Foldback protection disables the power supply’s output, turns on the ALM (alarm)LED and flashes the FOLD LED.4. There are 2 modes of releasing an activated Foldback protection.1. Short press on FOLD pushbutton enables the output and re-arms the protection circuit. If the loadis smaller than the current limit level, the power supply will restore normal operation. If the load isgreater than the current limit level, the output will be disabled again and Foldback indicators willbe on.2. Long press (approx. 3sec) on FOLD pushbutton will disable the Foldback protection circuit andenable the output. The power supply will restore operation to Constant Voltage or ConstantCurrent mode depending on the load characteristics and power supply setting.1. Rear panel ON/OFF Control2. Front panel ON/OFF ControlContacts 9, 10 at the rear panel External Control connector (fig. 4-2, item 4) serve as ON/OFFterminals. Either short circuit or TTL ‘0’ level enables the power supply output and open circuit or TTL ‘1’level disables the power supply’s output. An open collector transistor can be used for the ON/OFFcontrol as shown in fig. 4-3, with sink current ability of more than 2.5mA. Please note that pin 10 (COM)is internally connected to the - Sense potential, therefore for floating ON/OFF Control a photocouplershould be used as shown in Fig. 4-4.The Front Panel ON/OFF is controlled by the OUT pushbutton. To enable the output, OUT pushbuttonshould be pressed so that OUT LED illuminates. The operation of OUT pushbutton is enabled only if therear panel ON/OFF is configured to ‘ON’.Fig. 4-3: ON/OFF Control, references to - Sense.(ZUP rear panel view)Fig. 4-4: Floating ON/OFF Control(ZUP rear panel view)2 2- LS - LS- S - S+LS +LS+S +SOn/Off On/Off2.5mAON ONOFF OFFCOM COMP PVRFV VRFVVCVP VCVPVRFI VRFIVCCP VCCPRCVP RCVPRCCP RCCP1 1Output Good Output Good